1. Field of the Invention
This invention relates to a method of providing a private circuit in a telecommunications network which has at least two local switches, each local switch having a group of local access lines. The invention is also concerned with such a network which is arranged to provide a private circuit.
2. Related Art
In the usual method of providing a private circuit, the private circuit is provided by permanent, fixed transmission links between two local access lines. Such private circuits utilise valuable network capacity on a permanent basis and the provision of such circuits is labour intensive. It would be desirable to provide a variation of the usual private circuit service in which a circuit could be both set up for a short duration and then disconnected automatically by either the operator of the network or by a customer of the network.
A private virtual network is described in U.S. Pat. No. 4348554.
According to one aspect of this invention, there is provided a method of providing a private circuit in a telecommunications network between a first local access line and a second local access line, said network having at least two local switches and a switching unit, each local switch being connected to a group of local access lines, said method comprising the steps of:
instructing the switching unit to form a connection between the first local access line and the second local access line;
the switching unit calling the first local access line;
the switching unit calling the second local access line; and
the switching unit forming a connection between the first and second local access lines within itself so as to form a private circuit between the first and second local access lines.
This method provides the advantage that the user of the network can set up a private circuit automatically without creating permanent, fixed transmission links.
According to another aspect of this invention there is provided a telecommunications network having at least two local switches and a switching unit, each local switch being connected to a group of local access lines, said switching unit comprising:
means for receiving a call from a user in which the user instructs the switching unit to form a private circuit between a first local access line and a second local access line;
means for calling a first local access line;
means for calling a second local access line; and
means for forming a connection between a first local access line and a second local access lines within itself so as to form a private circuit between the first and second local access lines.